We know that politicians and corporations game the system already with fake accounts, presumably as a tool for manipulating public opinion. We know from the code that user comments aren't encrypted at all, or their voting tallies. It would require a very small tweak to manipulate things from the server side.
Given that, users should _not_ have been placing any trust in the sanctity of the results they see to tell them how the hive actually thinks or even if the linked source is accurate. People need to learn to question the motives of what's presented to them. I'm not saying to automatically distrust everything, just to look past whatever spin is put on an article and look at the primary sources.
The fact that someone has the capability and willingness to edit comments was so shocking to some people is a sign that these surprised people needed this kind of a wake-up call.
We can speculate, due to the missing warrant canary, that the government has, or has had, at least one user under surveillance from the system. This is very public proof that even the content of comments can be manipulated, which might help some poor schmuck out one day when his 'anonymous' internet comment gets misconstrued and comes back to bite him.